Green layer of stuff on top of the water in my salt water tank?

Question

I've had this green layer of..... well I don't really know. It's been there for a couple of months, and goes away with water changes, but returns within a few days. I've tried using different water (distilled and tap) and salt, and trying numerous water changes, but nothings happened. I've got a 20 gallon set up with a yellow tang, percula clown, mandarin dragonet, mushroom polyps, a condi-lactis anemone, and emerald crap, and numerous kinds of algea (all being green in color, so the basic). I seem to be getting the problem after putting PhytoPlex into the water. I have bought a different bottle of it and it still persists. I put in the same amount I have before. I put in about a half a teaspoon. I was putting in more previously (about 2 teaspoons) when I was directed to use only half a teaspoon a few months back. What could be my problem?

Answer 1

Your tank is getting WAY overstocked! The tang is small right now (I hope) but will eventually get around7-8 inces and these guys are active - the minimum you should have for these is a 55-75 gallon. Also, you should have at least a 40 gallon with lots of live rock for the dragonet. These guys are almost exclusively live-food eaters, so you need a lot of rock for the copepods to reproduce sufficiently to keep them fed. If it should happen to die in the tank, their skin secretes a toxin that could be bad news for your other animals.

Getting to your actual question...is this stuff fairly thick and bluish-green (see photo: http://www.aquamax.de/Shop/Artikelbilder/Zusatzbilder/Algen%20im%20Aquarium_Blaualgen%20-%20Cyanobacteria_STUG_cyano1.jpg ) sticking to the sides, but floating out onto the water surface? This would be cyanobacteria. I used the Phytoplex one time, and it introduced red cyanobacteria (http://www.sloreef.com/bojan/Cyanobacteria_files/Cyanobacteria1.jpg ) to my tank, so I stopped using it. So I'll mention that as a possibility.

I think what you're seeing might be more of a "film" on the water's surface. That's a natural occurance of bacteria and dissolved protein. Typically, you don't see this if you use a protein skimmer, but you may not have one for a 20 gallon. Another way to get rid of this is to use a surface skimmer, which connects to your power filter: http://www.thatpetplace.com/pet/prod/215642/product.web

Although both will remove the film, the surface skimmers aren't as good overall. They trap the film in your filter media, where bacteria break it down, but the ammonia, nitrite, and nitrate stay in your water. With a protein skimmer, the film is removed from the water and forced into a cup which you can dump periodically. Protein skimmers also remove a lot more of the dissolved material than the surface skimmer will, but the also cost more.

If this seems to be something else, could you post a photo?

PS - I hope what you have is an emerald CRAB!

Answer 2

it is somewhat ordinary for each new device to pass with the aid of algae blooms. upload a cleanser group and do water changes with RO/DI water. it is a nutrient concern reason from extra phosphates and nitrates. Do you run a protien skimmer on the tank? what procedures of nutrient export do you employ? As somebody else reported including some snails alongside with some sandsifters/sandshifters, will help save the algae in line. examine your phosphates and identity be keen to guess they are over 0.05. making use of RO?DI water for water changes alongside with a cleanser group and a protien skimmer will help save the priority in examine.